[zbin] Perform extra normalisation after completing decompression

LZMA performs an extra normalisation after decompression is complete,
which does not affect the output but may consume an extra byte from
the input (and so may affect which byte is identified as being the
start of the next block).

Reported-by: Robin Smidsrød <robin@smidsrod.no>
Tested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/i386/prefix/unlzma.S

 1:	/* Decompress until we reach end of buffer */
 	call	lzma_decode
 	jnc	1b
+	call	rc_normalise
 	print_character '\n'
 	/* Undo BCJ filter */
 	pushl	%esi