xtensa: localize labels used in memmove

Internal labels in the memmove implementation don't need to be visible,
localize them by prefixing their names with '.L'.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/lib/memcopy.S

@@ -402,13 +402,13 @@ WEAK(memmove)
 	 */
 	# copy 16 bytes per iteration for word-aligned dst and word-aligned src
 #if XCHAL_HAVE_LOOPS
-	loopnez	a7, .backLoop1done
+	loopnez	a7, .LbackLoop1done
 #else /* !XCHAL_HAVE_LOOPS */
-	beqz	a7, .backLoop1done
+	beqz	a7, .LbackLoop1done
 	slli	a8, a7, 4
 	sub	a8, a3, a8	# a8 = start of first 16B source chunk
 #endif /* !XCHAL_HAVE_LOOPS */
-.backLoop1:
+.LbackLoop1:
 	addi	a3, a3, -16
 	l32i	a7, a3, 12
 	l32i	a6, a3,  8
@@ -420,9 +420,9 @@ WEAK(memmove)
 	s32i	a7, a5,  4
 	s32i	a6, a5,  0
 #if !XCHAL_HAVE_LOOPS
-	bne	a3, a8, .backLoop1  # continue loop if a3:src != a8:src_start
+	bne	a3, a8, .LbackLoop1  # continue loop if a3:src != a8:src_start
 #endif /* !XCHAL_HAVE_LOOPS */
-.backLoop1done:
+.LbackLoop1done:
 	bbci.l	a4, 3, .Lback2
 	# copy 8 bytes
 	addi	a3, a3, -8
@@ -479,13 +479,13 @@ WEAK(memmove)
 #endif
 	l32i	a6, a3, 0	# load first word
 #if XCHAL_HAVE_LOOPS
-	loopnez	a7, .backLoop2done
+	loopnez	a7, .LbackLoop2done
 #else /* !XCHAL_HAVE_LOOPS */
-	beqz	a7, .backLoop2done
+	beqz	a7, .LbackLoop2done
 	slli	a10, a7, 4
 	sub	a10, a3, a10	# a10 = start of first 16B source chunk
 #endif /* !XCHAL_HAVE_LOOPS */
-.backLoop2:
+.LbackLoop2:
 	addi	a3, a3, -16
 	l32i	a7, a3, 12
 	l32i	a8, a3,  8
@@ -501,9 +501,9 @@ WEAK(memmove)
 	__src_b	a9, a6, a9
 	s32i	a9, a5,  0
 #if !XCHAL_HAVE_LOOPS
-	bne	a3, a10, .backLoop2 # continue loop if a3:src != a10:src_start
+	bne	a3, a10, .LbackLoop2 # continue loop if a3:src != a10:src_start
 #endif /* !XCHAL_HAVE_LOOPS */
-.backLoop2done:
+.LbackLoop2done:
 	bbci.l	a4, 3, .Lback12
 	# copy 8 bytes
 	addi	a3, a3, -8