LibC: Don't assert on unknown mode character in fopen()

Just carry on with some debug log whining.
Gets rid of one dropbear patch. :^)

Libraries/LibC/stdio.cpp

@@ -913,8 +913,8 @@ static int parse_mode(const char* mode)
 
     // NOTE: rt is a non-standard mode which opens a file for read, explicitly
     // specifying that it's a text file
-    for (; *mode; ++mode) {
+    for (auto* ptr = mode; *ptr; ++ptr) {
-        switch (*mode) {
+        switch (*ptr) {
         case 'r':
             flags |= O_RDONLY;
             break;
@@ -937,8 +937,7 @@ static int parse_mode(const char* mode)
             // Ok...
             break;
         default:
-            dbg() << "Unsupported mode _" << mode << "_ (because of '" << *mode << "')";
+            dbg() << "Potentially unsupported fopen mode _" << mode << "_ (because of '" << *ptr << "')";
-            ASSERT_NOT_REACHED();
         }
     }
 

Ports/dropbear/patches/fopen-c.patch

@@ -1,11 +0,0 @@
---- a/compat.c
-+++ b/compat.c
-@@ -244,7 +244,7 @@
- 	if (strings != NULL)
- 		free(strings);
- 	strings = NULL;
--	if ((fp = fopen("/etc/shells", "rc")) == NULL)
-+	if ((fp = fopen("/etc/shells", "r")) == NULL)
- 		return (char **) okshells;
- 	if (fstat(fileno(fp), &statb) == -1) {
- 		(void)fclose(fp);