patch 8.2.4127: build failure without the +eval feature

Problem:    Build failure without the +eval feature.
Solution:   Add #ifdef.
diff --git a/src/usercmd.c b/src/usercmd.c
index 808d36c..015a9c1 100644
--- a/src/usercmd.c
+++ b/src/usercmd.c
@@ -548,6 +548,7 @@
 		{
 		    STRCPY(IObuff + len, command_complete[j].name);
 		    len += (int)STRLEN(IObuff + len);
+#ifdef FEAT_EVAL
 		    if (p_verbose > 0 && cmd->uc_compl_arg != NULL
 					    && STRLEN(cmd->uc_compl_arg) < 200)
 		    {
@@ -555,6 +556,7 @@
 			STRCPY(IObuff + len + 1, cmd->uc_compl_arg);
 			len += (int)STRLEN(IObuff + len);
 		    }
+#endif
 		    break;
 		}