patch 8.1.1414: alloc() returning "char_u *" causes a lot of type casts

Problem:    Alloc() returning "char_u *" causes a lot of type casts.
Solution:   Have it return "void *". (Mike Williams)  Define ALLOC_ONE() to
            check the simple allocations.
diff --git a/src/search.c b/src/search.c
index 20e619d..423f3fc 100644
--- a/src/search.c
+++ b/src/search.c
@@ -5145,8 +5145,7 @@
 	    goto fpip_end;
 	def_regmatch.rm_ic = FALSE;	/* don't ignore case in define pat. */
     }
-    files = (SearchedFile *)lalloc_clear(
-				  max_path_depth * sizeof(SearchedFile), TRUE);
+    files = lalloc_clear(max_path_depth * sizeof(SearchedFile), TRUE);
     if (files == NULL)
 	goto fpip_end;
     old_files = max_path_depth;
@@ -5306,8 +5305,7 @@
 		/* Push the new file onto the file stack */
 		if (depth + 1 == old_files)
 		{
-		    bigger = (SearchedFile *)alloc(
-				    max_path_depth * 2 * sizeof(SearchedFile));
+		    bigger = ALLOC_MULT(SearchedFile, max_path_depth * 2);
 		    if (bigger != NULL)
 		    {
 			for (i = 0; i <= depth; i++)