main/backtrace: binutils-2.34 fix.

My tester missed this one previously, have confirmed a positive build
this time round.

Change-Id: Id06853375954a200f03f9a1b9c97fe0b10d31fbf

main/backtrace.c

@@ -65,6 +65,9 @@
 #ifndef bfd_get_section_vma
 #define bfd_get_section_vma(x, y)	bfd_section_vma(y)
 #endif
+#ifndef bfd_get_section_flags
+#define bfd_get_section_flags(x, y) bfd_section_flags(y)
+#endif
 #endif
 
 #include <pthread.h>