Bug#43572 Handle failures from hash_init

This patch is a follow up to http://lists.mysql.com/commits/76678.
When an allocation failure occurs for the buffer in the dynamic
array, an error condition was being set. The dynamic array is
usable even if the memory allocation fails. Since in most cases
the thread can continue to work without any problems the error
condition should not be set here.

This patch adds logic to remove the error condition from being set
when the memory allocation for the buffer in dynamic array fails.

mysys/array.c:
  Bug#43572 Handle failures from hash_init
  
  Remove the MY_WME flag from the call to malloc in order to
  prevent the error status from being set in the init_dynamic_array
  method. Since this memory allocation failure is no longer
  fatal this method has been modified to return FALSE
  (indicate success) irrespective of array->buffer being
  allocated.

mysys/array.c

@@ -31,10 +31,10 @@
   DESCRIPTION
     init_dynamic_array() initiates array and allocate space for 
     init_alloc eilements. 
-    Array is usable even if space allocation failed.
+    Array is usable even if space allocation failed, hence, the
+    function never returns TRUE.
 
   RETURN VALUE
-    TRUE	my_malloc_ci() failed
     FALSE	Ok
 */
 
@@ -56,11 +56,12 @@ my_bool init_dynamic_array(DYNAMIC_ARRAY *array, uint element_size,
   array->max_element=init_alloc;
   array->alloc_increment=alloc_increment;
   array->size_of_element=element_size;
-  if (!(array->buffer=(char*) my_malloc_ci(element_size*init_alloc,MYF(MY_WME))))
-  {
+  /* 
+    Since the dynamic array is usable even if allocation fails here malloc
+    should not throw an error
+  */
+  if (!(array->buffer= (char*) my_malloc_ci(element_size*init_alloc, MYF(0))))
     array->max_element=0;
-    DBUG_RETURN(TRUE);
-  }
   DBUG_RETURN(FALSE);
 }