fix bug 2603717. Ensure all elf program headers are copied.

fix bug 2603717.  Ensure all elf program headers are copied.

When stripping a binary, soslim calls adjust_elf.  adjust_elf
copies over the elf program headers, making adjustments
as necessary.  Under some circumstances, the code which loops
over all the program headers will fail to call gelf_update_phdr().
Instead of copying over the elf program header from the old
binary to the new binary, a "NULL" header is written to the
binary.

Change-Id: I7afdc8e3af2638c386546f1bfe4f151e1f002087