Strip LOCAL_CHECK_ELF_FILES

This commit strips LOCAL_CHECK_ELF_FILES before comparing it with
`false` so that developers can add comments after LOCAL_CHECK_ELF_FILES.
For example:

    LOCAL_CHECK_ELF_FILES := false  # disable checks due to ...

Bug: 119084334
Test: Add some spaces after LOCAL_CHECK_ELF_FILES and run
      CHECK_ELF_FILES=true make check-elf-files
Change-Id: I2bfaff4807aeeea6c7af0b9d7d716742b6764cd0
diff --git a/core/check_elf_file.mk b/core/check_elf_file.mk
index 69d891c..8f2eafb 100644
--- a/core/check_elf_file.mk
+++ b/core/check_elf_file.mk
@@ -35,7 +35,7 @@
 	$(hide) touch $@
 
 ifneq ($(PRODUCT_CHECK_ELF_FILES)$(CHECK_ELF_FILES),)
-ifneq ($(LOCAL_CHECK_ELF_FILES),false)
+ifneq ($(strip $(LOCAL_CHECK_ELF_FILES)),false)
 $(LOCAL_BUILT_MODULE): $(check_elf_files_stamp)
 check-elf-files: $(check_elf_files_stamp)
 endif  # LOCAL_CHECK_ELF_FILES