tweaks: elide two unneeded variables from line numbering mode

Instead compute directly whether we're at a softwrapped part or not.

src/global.c

@@ -49,12 +49,6 @@ int margin = 0;
 	/* The amount of space reserved at the left for line numbers. */
 int editwincols = -1;
 	/* The number of usable columns in the edit window: COLS - margin. */
-#ifdef ENABLE_LINENUMBERS
-int last_drawn_line = 0;
-        /* The line number of the last drawn line. */
-int last_line_y;
-        /* The y coordinate of the last drawn line. */
-#endif
 
 message_type lastmessage = HUSH;
 	/* Messages of type HUSH should not overwrite type MILD nor ALERT. */

src/proto.h

@@ -40,10 +40,6 @@ extern bool focusing;
 
 extern int margin;
 extern int editwincols;
-#ifdef ENABLE_LINENUMBERS
-extern int last_drawn_line;
-extern int last_line_y;
-#endif
 
 extern message_type lastmessage;
 

src/winio.c

@@ -2322,10 +2322,12 @@ void edit_draw(filestruct *fileptr, const char *converted, int
      * the text -- but only for the parts that are not softwrapped. */
     if (margin > 0) {
 	wattron(edit, interface_color_pair[LINE_NUMBER]);
-	if (last_drawn_line != fileptr->lineno || last_line_y >= line)
+#ifndef NANO_TINY
-	    mvwprintw(edit, line, 0, "%*ld", margin - 1, (long)fileptr->lineno);
+	if (ISSET(SOFTWRAP) && (startpos / editwincols > 0))
-	else
 	    mvwprintw(edit, line, 0, "%*s", margin - 1, " ");
+	else
+#endif
+	    mvwprintw(edit, line, 0, "%*ld", margin - 1, (long)fileptr->lineno);
 	wattroff(edit, interface_color_pair[LINE_NUMBER]);
     }
 #endif
@@ -2693,10 +2695,6 @@ void edit_draw(filestruct *fileptr, const char *converted, int
 	}
     }
 #endif /* !NANO_TINY */
-#ifdef ENABLE_LINENUMBERS
-    last_drawn_line = fileptr->lineno;
-    last_line_y = line;
-#endif
 }
 
 /* Just update one line in the edit buffer.  This is basically a wrapper