PATCH: Fix seg-fault in MIPS linkers

[Alan Modra]

After Nick's commit the only changes I noticed were for this mips target:

CFLAGS="-g -O -fno-inline" /src/binutils-current/configure --prefix=/usr/local --disable-nls --build=i586-linux --target=tx39-elf

A quick look shows that elf_bad_symtab is set, so you end up loading a
NULL from sym_hashes for local syms.

-- 
Alan Modra
Australia Development Lab, IBM