ia64 gas: Remove unnecessary init

The whole struct is cleared by alloc_record.

	* config/tc-ia64.c (output_prologue, output_prologue_gr): Don't
	zero r.record.r.mask.
diff --git a/gas/config/tc-ia64.c b/gas/config/tc-ia64.c
index 2c5e45f..a455504 100644
--- a/gas/config/tc-ia64.c
+++ b/gas/config/tc-ia64.c
@@ -1760,7 +1760,6 @@
 output_prologue (void)
 {
   unw_rec_list *ptr = alloc_record (prologue);
-  memset (&ptr->r.record.r.mask, 0, sizeof (ptr->r.record.r.mask));
   return ptr;
 }
 
@@ -1768,7 +1767,6 @@
 output_prologue_gr (unsigned int saved_mask, unsigned int reg)
 {
   unw_rec_list *ptr = alloc_record (prologue_gr);
-  memset (&ptr->r.record.r.mask, 0, sizeof (ptr->r.record.r.mask));
   ptr->r.record.r.grmask = saved_mask;
   ptr->r.record.r.grsave = reg;
   return ptr;