ARM: 8939/1: kbuild: use correct nm executable

Since $(NM) variable can be easily overridden for the whole build, it's
better to use it instead of $(CROSS_COMPILE)nm. The use of $(CROSS_COMPILE)
prefixed variables where their calculated equivalents can be used is
incorrect. This fixes issues with builds where $(NM) is set to llvm-nm.

Link: https://github.com/ClangBuiltLinux/linux/issues/766

Signed-off-by: Dmitry Golovin <dima@golovin.in>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Matthias Maennich <maennich@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/boot/compressed/Makefile

@@ -121,7 +121,7 @@ ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin -I$(obj)
 asflags-y := -DZIMAGE
 
 # Supply kernel BSS size to the decompressor via a linker symbol.
-KBSS_SZ = $(shell echo $$(($$($(CROSS_COMPILE)nm $(obj)/../../../../vmlinux | \
+KBSS_SZ = $(shell echo $$(($$($(NM) $(obj)/../../../../vmlinux | \
 		sed -n -e 's/^\([^ ]*\) [AB] __bss_start$$/-0x\1/p' \
 		       -e 's/^\([^ ]*\) [AB] __bss_stop$$/+0x\1/p') )) )
 LDFLAGS_vmlinux = --defsym _kernel_bss_size=$(KBSS_SZ)
@@ -165,7 +165,7 @@ $(obj)/bswapsdi2.S: $(srctree)/arch/$(SRCARCH)/lib/bswapsdi2.S
 # The .data section is already discarded by the linker script so no need
 # to bother about it here.
 check_for_bad_syms = \
-bad_syms=$$($(CROSS_COMPILE)nm $@ | sed -n 's/^.\{8\} [bc] \(.*\)/\1/p') && \
+bad_syms=$$($(NM) $@ | sed -n 's/^.\{8\} [bc] \(.*\)/\1/p') && \
 [ -z "$$bad_syms" ] || \
   ( echo "following symbols must have non local/private scope:" >&2; \
     echo "$$bad_syms" >&2; false )