[PATCH] objtool: use $(SRCARCH) to avoid compile error with ARCH=x86_64

[Shile Zhang]

To build objtool with ARCH=x86_64 will failed as:

   $make ARCH=x86_64 -C tools/objtool
   ...
     CC       arch/x86/decode.o
   arch/x86/decode.c:10:22: fatal error: asm/insn.h: No such file or directory
    #include <asm/insn.h>
                         ^
   compilation terminated.
   mv: cannot stat âarch/x86/.decode.o.tmpâ: No such file or directory
   make[2]: *** [arch/x86/decode.o] Error 1
   ...

The root cause is the command-line variable 'ARCH' cannot be overridden.
It can be replaced by the one 'SRCARCH' defined in
'tools/scripts/Makefile.arch'.

Signed-off-by: Shile Zhang <shile.zhang@xxxxxxxxxxxxxxxxx>
---
 tools/objtool/Makefile | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index d2a19b0bc05a..ee08aeff30a1 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -2,10 +2,6 @@
 include ../scripts/Makefile.include
 include ../scripts/Makefile.arch
 
-ifeq ($(ARCH),x86_64)
-ARCH := x86
-endif
-
 # always use the host compiler
 HOSTAR	?= ar
 HOSTCC	?= gcc
@@ -33,7 +29,7 @@ all: $(OBJTOOL)
 
 INCLUDES := -I$(srctree)/tools/include \
 	    -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
-	    -I$(srctree)/tools/arch/$(ARCH)/include
+	    -I$(srctree)/tools/arch/$(SRCARCH)/include
 WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed
 CFLAGS   := -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
 LDFLAGS  += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
-- 
2.24.0.rc2