patch 8.1.1386: unessesary type casts for lalloc()

Problem:    Unessesary type casts for lalloc().
Solution:   Remove type casts.  Change lalloc(size, TRUE) to alloc(size).
diff --git a/src/regexp.c b/src/regexp.c
index 3697cd9..b090389 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -1319,7 +1319,7 @@
 	return NULL;
 
     /* Allocate space. */
-    r = (bt_regprog_T *)lalloc(sizeof(bt_regprog_T) + regsize, TRUE);
+    r = (bt_regprog_T *)alloc(sizeof(bt_regprog_T) + regsize);
     if (r == NULL)
 	return NULL;
     r->re_in_use = FALSE;
@@ -3932,7 +3932,7 @@
 {
     reg_extmatch_T	*em;
 
-    em = (reg_extmatch_T *)alloc_clear((unsigned)sizeof(reg_extmatch_T));
+    em = (reg_extmatch_T *)alloc_clear(sizeof(reg_extmatch_T));
     if (em != NULL)
 	em->refcnt = 1;
     return em;
@@ -7830,7 +7830,7 @@
 
 	    if (retval == NULL)
 	    {
-		retval = lalloc((long_u)len, TRUE);
+		retval = alloc(len);
 		if (retval == NULL)
 		    return NULL;
 	    }