unstrip: Check symbol strings are terminated. A corrupt ELF file could contain a .strtab section that wasn't properly zero terminated. If so we could add a non-terminated string to the dwelf_strtab functions, which could then crash because they would read past the .strtab section data. https://sourceware.org/bugzilla/show_bug.cgi?id=25069 Signed-off-by: Mark Wielaard <[email protected]>