commonlib/endian: Restore -Warray-bounds at the end of file

commit 668ea970 ("commonlib/endian: Silence GCC -Warray-bounds false
positives") added `#pragma GCC diagnostic ignored "-Warray-bounds"` but
forgot to restore the diagnostic state at the end of the file.

Change-Id: I41b38758ce862490777ede63ff92d95d6ba21521
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/89867
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/commonlib/include/commonlib/endian.h

@@ -252,4 +252,5 @@ static inline void zero_n(void *dest, size_t n)
 	memset(dest, 0, n);
 }
 
+#pragma GCC diagnostic pop /* restore -Warray-bounds */
 #endif /* _COMMONLIB_ENDIAN_H_ */