tools/resolve_btfids: Fix build when cross compiling kernel with clang.

When cross compiling the kernel with clang, we need to override
CLANG_CROSS_FLAGS when preparing the step libraries.

Prior to commit d1d096312176 ("tools: fix annoying "mkdir -p ..." logs
when building tools in parallel"), MAKEFLAGS would have been set to a
value that wouldn't set a value for CLANG_CROSS_FLAGS, hiding the
fact that we weren't properly overriding it.

Fixes: 56a2df7615fa ("tools/resolve_btfids: Compile resolve_btfids as host program")
Signed-off-by: Suleiman Souhlal <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/bpf/[e-mail]

tools/bpf/resolve_btfids/Makefile

···
 
 # Overrides for the prepare step libraries.
 HOST_OVERRIDES := AR="$(HOSTAR)" CC="$(HOSTCC)" LD="$(HOSTLD)" ARCH="$(HOSTARCH)" \
-		  CROSS_COMPILE="" EXTRA_CFLAGS="$(HOSTCFLAGS)"
+		  CROSS_COMPILE="" CLANG_CROSS_FLAGS="" EXTRA_CFLAGS="$(HOSTCFLAGS)"
 
 RM      ?= rm
 HOSTCC  ?= gcc