ftrace: scripts/recordmcount.pl cross-build hack

hack around:

 ld: Relocatable linking with relocations from format elf32-i386 (init/.tmp_gl_calibrate.o) to format elf64-x86-64 (init/.tmp_mx_calibrate.o) i  CC      arch/x86/mm/extable.o
 objcopy: 'init/.tmp_mx_calibrate.o': No such file
 rm: cannot remove `init/.tmp_mx_calibrate.o': No such file or directory
 ld: Relocatable linking with relocations from format elf32-i386 (arch/x86/mm/extable.o) to format elf64-x86-64 (arch/x86/mm/.tmp_mx_extable.o) is not supported
 mv: cannot stat `arch/x86/mm/.tmp_mx_extable.o': No such file or directory
 ld: Relocatable linking with relocations from format elf32-i386 (arch/x86/mm/fault.o) to format elf64-x86-64 (arch/x86/mm/.tmp_mx_fault.o) is not supported

Signed-off-by: Ingo Molnar <mingo@elte.hu>