tweaks: chuck an assert, and then condense the code and a comment

src/search.c

@@ -65,21 +65,14 @@ void regexp_cleanup(void)
     }
 }
 
-/* Indicate on the statusbar that the string at str was not found by the
- * last search. */
+/* Report on the status bar that the given string was not found. */
 void not_found_msg(const char *str)
 {
-    char *disp;
-    size_t numchars;
-
-    assert(str != NULL);
-
-    disp = display_string(str, 0, (COLS / 2) + 1, FALSE);
-    numchars = actual_x(disp, strnlenpt(disp, COLS / 2));
+    char *disp = display_string(str, 0, (COLS / 2) + 1, FALSE);
+    size_t numchars = actual_x(disp, strnlenpt(disp, COLS / 2));
 
     statusline(HUSH, _("\"%.*s%s\" not found"), numchars, disp,
 		(disp[numchars] == '\0') ? "" : "...");
-
     free(disp);
 }