Fixed set-but-not-used compiler (gcc) warnings.

Details:
- Used void-casts of certain variables to appease gcc (and perhaps other
  compilers) when such variables are only used in the complex instances of
  the functions. Special thanks to Karl Rupp for suggesting a portable fix
  for these warnings.

frame/2/her/bli_her_unb_var1.c

@@ -135,6 +135,9 @@ void PASTEMAC2(chx,chc,varname)( \
 	dim_t     n_behind; \
 	inc_t     rs_ct, cs_ct; \
 	conj_t    conj0, conj1; \
+\
+	/* Eliminate unused variable warnings. */ \
+	( void )conj0; \
 \
 	if ( bli_zero_dim1( m ) ) return; \
 \

frame/2/her/bli_her_unb_var2.c

@@ -135,6 +135,9 @@ void PASTEMAC2(chx,chc,varname)( \
 	dim_t     n_ahead; \
 	inc_t     rs_ct, cs_ct; \
 	conj_t    conj0, conj1; \
+\
+	/* Eliminate unused variable warnings. */ \
+	( void )conj0; \
 \
 	if ( bli_zero_dim1( m ) ) return; \
 \

frame/2/her2/bli_her2_unb_var2.c

@@ -156,6 +156,9 @@ void PASTEMAC3(chx,chy,chc,varname)( \
 	inc_t     rs_ct, cs_ct; \
 	conj_t    conj0, conj1; \
 	conj_t    conjh_conjy; \
+\
+	/* Eliminate unused variable warnings. */ \
+	( void )conjh_conjy; \
 \
 	if ( bli_zero_dim1( m ) ) return; \
 \

frame/2/her2/bli_her2_unb_var3.c

@@ -156,6 +156,9 @@ void PASTEMAC3(chx,chy,chc,varname)( \
 	inc_t     rs_ct, cs_ct; \
 	conj_t    conj0, conj1; \
 	conj_t    conjh_conjx; \
+\
+	/* Eliminate unused variable warnings. */ \
+	( void )conjh_conjx; \
 \
 	if ( bli_zero_dim1( m ) ) return; \
 \

frame/2/her2/bli_her2_unb_var4.c

@@ -155,6 +155,10 @@ void PASTEMAC3(chx,chy,chc,varname)( \
 	conj_t    conj0, conj1; \
 	conj_t    conjh_conjx; \
 	conj_t    conjh_conjy; \
+\
+	/* Eliminate unused variable warnings. */ \
+	( void )conjh_conjx; \
+	( void )conjh_conjy; \
 \
 	if ( bli_zero_dim1( m ) ) return; \
 \

frame/2/her2/bli_her2_unf_var4.c

@@ -155,6 +155,10 @@ void PASTEMAC3(chx,chy,chc,varname)( \
 	conj_t    conj0, conj1; \
 	conj_t    conjh_conjx; \
 	conj_t    conjh_conjy; \
+\
+	/* Eliminate unused variable warnings. */ \
+	( void )conjh_conjx; \
+	( void )conjh_conjy; \
 \
 	if ( bli_zero_dim1( m ) ) return; \
 \

frame/3/her2k/bli_her2k.c

@@ -46,7 +46,7 @@ void bli_her2k( obj_t*  alpha,
                 obj_t*  beta,
                 obj_t*  c )
 {
-	her2k_t* cntl;
+	//her2k_t* cntl;
 	obj_t    alpha_local;
 	obj_t    alpha_conj_local;
 	obj_t    beta_local;
@@ -133,10 +133,10 @@ void bli_her2k( obj_t*  alpha,
 
 	if ( pack_c ) bli_check_error_code( BLIS_NOT_YET_IMPLEMENTED );
 
+/*
 	// Choose the control tree.
 	cntl = her2k_cntl;
 
-/*
 	// Invoke the internal back-end.
 	bli_her2k_int( &alpha_local,
 	               &a_local,

frame/util/mkherm/bli_mkherm_unb_var1.c

@@ -83,6 +83,9 @@ void PASTEMAC(ch,varname)( \
 	ctype*  alpha11; \
 	doff_t  diagoffa; \
 	dim_t   i; \
+\
+	/* Eliminate unused variable warnings. */ \
+	( void )alpha11; \
 \
 	/* If the dimension is zero, return early. */ \
 	if ( bli_zero_dim1( m ) ) return; \