package/linux-tools: perf: Disable shellcheck

The use of shellcheck within perf is not a functional requirement and it can
lead to build failures where the perf makefile attempts to link in empty
.shellcheck_log files:

https://lore.kernel.org/r/fb078045-dc05-426e-b21e-72ffae3e8e1b@gmail.com

Disable shellcheck since we do not need it at all.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 0c44722b0ca6c1ab7d0f7af6a703361f553e4747)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/linux-tools/linux-tool-perf.mk.in

@@ -28,7 +28,8 @@ PERF_MAKE_FLAGS = \
 	NO_LIBPERL=1 \
 	NO_LIBPYTHON=1 \
 	NO_LIBBIONIC=1 \
-	NO_LIBTRACEEVENT=1
+	NO_LIBTRACEEVENT=1 \
+	NO_SHELLCHECK=1
 
 # We need to pass an argument to ld for setting the emulation when
 # building for MIPS architecture, otherwise the default one will always