x86/mpx: Remove selftests Makefile entry

MPX is being removed from the kernel due to a lack of support in the
toolchain going forward (gcc).

This is the smallest possible patch to fix some issues that have been
reported around running the MPX selftests.  It it would also have been part
of any removal series, it is offered first.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190705175318.784C233E@viggo.jf.intel.com

Author: hansendc

tools/testing/selftests/x86/Makefile

@@ -11,7 +11,7 @@ CAN_BUILD_X86_64 := $(shell ./check_cc.sh $(CC) trivial_64bit_program.c)
 CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh $(CC) trivial_program.c -no-pie)
 
 TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \
-			check_initial_reg_state sigreturn iopl mpx-mini-test ioperm \
+			check_initial_reg_state sigreturn iopl ioperm \
 			protection_keys test_vdso test_vsyscall mov_ss_trap \
 			syscall_arg_fault
 TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \