MIPS/BFD: Correct an FP ABI warning

MIPS/BFD: Correct an FP ABI warning

Correct a warning produced on any FP ABI mismatch observed.  Unlike the
other settings, which in the presence of `.MIPS.abiflags' are duplicated
in the `e_flags' member of the ELF file header, information on the FP
ABI in use is duplicated in `.gnu.attributes' rather than in the former
place.  Update the warning message accordingly.

	bfd/
	* elfxx-mips.c (_bfd_mips_elf_merge_private_bfd_data): Correct
	an FP ABI warning.