Don't pass external input as format string. Detected by -Werror=format-security.

https://bugs.gentoo.org/530630
--- a/src/print.c
+++ b/src/print.c
@@ -1220,7 +1220,7 @@ static void print_job_ps_page_image_pixel(FILE *f, guchar *pix)
 		}
 	text[6] = '\0';
 
-	fprintf(f, text);
+	fprintf(f, "%s", text);
 }                                                                                                                         
 static gint print_job_ps_page_image(PrintWindow *pw, GdkPixbuf *pixbuf,
 				    gdouble x, gdouble y, gdouble w, gdouble h,
@@ -1345,7 +1345,7 @@ static const gchar *ps_text_to_hex_array(FILE *f, const gchar *text, gdouble x,
 		text[1] = hex_digits[*p & 0xf];
 		text[2] = '\0';
 
-		fprintf(f, text);
+		fprintf(f, "%s", text);
 
 		p++;
 		}
--- a/src/ui_fileops.c
+++ b/src/ui_fileops.c
@@ -44,7 +44,7 @@ void print_term(const gchar *text_utf8)
 	gchar *text_l;
 
 	text_l = g_locale_from_utf8(text_utf8, -1, NULL, NULL, NULL);
-	printf((text_l) ? text_l : text_utf8);
+	printf("%s", (text_l) ? text_l : text_utf8);
 	g_free(text_l);
 }
 
--- a/src/view_file_icon.c
+++ b/src/view_file_icon.c
@@ -614,7 +614,7 @@ static void vficon_dnd_get(GtkWidget *widget, GdkDragContext *context,
 	uri_text = uri_text_from_list(list, &total, (info == TARGET_TEXT_PLAIN));
 	path_list_free(list);
 
-	if (debug) printf(uri_text);
+	if (debug) printf("%s", uri_text);
 
 	gtk_selection_data_set(selection_data, selection_data->target,
 			       8, (guchar *)uri_text, total);
--- a/src/view_file_list.c
+++ b/src/view_file_list.c
@@ -136,7 +136,7 @@ static void vflist_dnd_get(GtkWidget *widget, GdkDragContext *context,
 	uri_text = uri_text_from_list(list, &total, (info == TARGET_TEXT_PLAIN));
 	path_list_free(list);
 
-	if (debug) printf(uri_text);
+	if (debug) printf("%s", uri_text);
 
 	gtk_selection_data_set(selection_data, selection_data->target,
 			       8, (guchar *)uri_text, total);