arm: Remove yet another unused variable.

Bootstrap found yet another unused variable:
../../gcc/config/arm/vfp.md:1651:17: warning: unused variable 'regname' [-Wunused-variable]

2020-01-18  Jakub Jelinek  <jakub@redhat.com>

	* config/arm/vfp.md (*clear_vfp_multiple): Remove unused variable.

gcc/ChangeLog

 2020-01-18  Jakub Jelinek  <jakub@redhat.com>
 
+	* config/arm/vfp.md (*clear_vfp_multiple): Remove unused variable.
+
 	PR target/93312
 	* config/arm/arm.c (clear_operation_p): Don't use REGNO until
 	after checking the argument is a REG.  Don't use REGNO (reg)

gcc/config/arm/vfp.md

@@ -1648,7 +1648,6 @@
   {
     int num_regs = XVECLEN (operands[0], 0);
     char pattern[30];
-    const char *regname;
     rtx reg;
 
     strcpy (pattern, \"vscclrm%?\\t{%|\");