objtool: Silence more KCOV warnings, part 2

Similar to GCOV, KCOV can leave behind dead code and undefined behavior.
Warnings related to those should be ignored.

The previous commit:

  6b023c7 ("objtool: Silence more KCOV warnings")

... only did so for CONFIG_CGOV_KERNEL.  Also do it for CONFIG_KCOV, but
for real this time.

Fixes the following warning:

  vmlinux.o: warning: objtool: synaptics_report_mt_data: unexpected end of section .text.synaptics_report_mt_data

Fixes: 6b023c7 ("objtool: Silence more KCOV warnings")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/a44ba16e194bcbc52c1cef3d3cd9051a62622723.1743481539.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202503282236.UhfRsF3B-lkp@intel.com/

Author: jpoimboe

scripts/Makefile.lib

@@ -275,7 +275,7 @@ objtool-args-$(CONFIG_MITIGATION_SLS)			+= --sls
 objtool-args-$(CONFIG_STACK_VALIDATION)			+= --stackval
 objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE)		+= --static-call
 objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION)		+= --uaccess
-objtool-args-$(CONFIG_GCOV_KERNEL)			+= --no-unreachable
+objtool-args-$(or $(CONFIG_GCOV_KERNEL),$(CONFIG_KCOV))	+= --no-unreachable
 objtool-args-$(CONFIG_PREFIX_SYMBOLS)			+= --prefix=$(CONFIG_FUNCTION_PADDING_BYTES)
 objtool-args-$(CONFIG_OBJTOOL_WERROR)			+= --Werror