MIPS: BPF: Avoid unreachable code on little endian

On little endian, avoid generating the big endian version of the code
by using #else in addition to #ifdef #endif. Also fix one alignment
issue wrt delay slot.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: stable@vger.kernel.org # v4.2+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11097/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/net/bpf_jit_asm.S

@@ -151,9 +151,10 @@ NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp)
 	wsbh	t0, $r_s0
 	jr	$r_ra
 	 rotr	$r_A, t0, 16
-#endif
+#else
 	jr	$r_ra
 	 move	$r_A, $r_s0
+#endif
 
 	END(bpf_slow_path_word)
 
@@ -162,9 +163,10 @@ NESTED(bpf_slow_path_half, (6 * SZREG), $r_sp)
 #ifdef CONFIG_CPU_LITTLE_ENDIAN
 	jr	$r_ra
 	 wsbh	$r_A, $r_s0
-#endif
+#else
 	jr	$r_ra
 	 move	$r_A, $r_s0
+#endif
 
 	END(bpf_slow_path_half)