kbuild: remove cc-option test of -fno-strict-overflow

The minimal compiler versions, GCC 4.9 and Clang 10 support this flag.

Here is the godbolt:
https://godbolt.org/z/odq8h9

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
diff --git a/Makefile b/Makefile
index 06890bb..7036dcb 100644
--- a/Makefile
+++ b/Makefile
@@ -928,7 +928,7 @@
 KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
 
 # disable invalid "can't wrap" optimizations for signed / pointers
-KBUILD_CFLAGS	+= $(call cc-option,-fno-strict-overflow)
+KBUILD_CFLAGS	+= -fno-strict-overflow
 
 # clang sets -fmerge-all-constants by default as optimization, but this
 # is non-conforming behavior for C and in fact breaks the kernel, so we