kheaders: avoid unnecessary process forks of grep

Exclude include/generated/{utsversion.h,autoconf.h} by using the -path
option to reduce the cost of forking new processes.

No functional changes are intended.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kernel/gen_kheaders.sh

@@ -48,9 +48,9 @@ all_dirs="$all_dirs $dir_list"
 # check include/generated/autoconf.h explicitly.
 #
 # Ignore them for md5 calculation to avoid pointless regeneration.
-headers_md5="$(find $all_dirs -name "*.h"			|
-		grep -v "include/generated/utsversion.h"	|
-		grep -v "include/generated/autoconf.h"	|
+headers_md5="$(find $all_dirs -name "*.h" -a			\
+		! -path include/generated/utsversion.h -a	\
+		! -path include/generated/autoconf.h		|
 		xargs ls -l | md5sum | cut -d ' ' -f1)"
 
 # Any changes to this script will also cause a rebuild of the archive.