kbuild: change filechk to surround the given command with { }

filechk_* rules often consist of multiple 'echo' lines. They must be
surrounded with { } or ( ) to work correctly. Otherwise, only the
string from the last 'echo' would be written into the target.

Let's take care of that in the 'filechk' in scripts/Kbuild.include
to clean up filechk_* rules.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/Makefile b/Makefile
index 04a8578..437d603 100644
--- a/Makefile
+++ b/Makefile
@@ -1127,13 +1127,13 @@
 	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
 	  exit 1;                                                         \
 	fi;                                                               \
-	(echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
+	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
 endef
 
 define filechk_version.h
-	(echo \#define LINUX_VERSION_CODE $(shell                         \
+	echo \#define LINUX_VERSION_CODE $(shell                         \
 	expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
-	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
+	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
 endef
 
 $(version_h): FORCE