kernel-build: fix STRIP_KERNEL_EXPORTS for recent kernels

Recent kernels started to mark exported symbols as global.
Adapt expressions in kernel-build.mk to also match global symbols
when grep'ing through nm output.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

SVN-Revision: 42555

include/kernel-build.mk

@@ -76,7 +76,7 @@ define BuildKernel
 		xargs $(TARGET_CROSS)nm | \
 		awk '$$$$1 == "U" { print $$$$2 } ' | \
 		sort -u > $(KERNEL_BUILD_DIR)/mod_symtab.txt
-	$(TARGET_CROSS)nm -n $(LINUX_DIR)/vmlinux.o | grep -F ' r __ksymtab' | sed -e 's,........ r __ksymtab_,,' > $(KERNEL_BUILD_DIR)/kernel_symtab.txt
+	$(TARGET_CROSS)nm -n $(LINUX_DIR)/vmlinux.o | grep ' [rR] __ksymtab' | sed -e 's,........ [rR] __ksymtab_,,' > $(KERNEL_BUILD_DIR)/kernel_symtab.txt
 	grep -Ff $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_include.txt
 	grep -Fvf $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_exclude.txt
 	( \