sh: Try to execute programs in /bin if they are not found

That is a common ocurrence.

apps/src/sh.c

@@ -1,3 +1,4 @@
+#include <errno.h>
 #include <luna.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -104,7 +105,18 @@ void command_execute(command* cmd)
     }
     if (child == 0)
     {
-        execv(cmd->buffer, NULL);
+        if (cmd->buffer[0] != '/' && access(cmd->buffer, F_OK) < 0) // FIXME: Race condition.
+        {
+            if (errno == ENOENT)
+            { // Try in /bin
+                char* buf = malloc(cmd->size + 6);
+                strlcpy(buf, "/bin/", 6);
+                strncat(buf, cmd->buffer, cmd->size);
+                execv(buf, NULL);
+            }
+        }
+        else
+            execv(cmd->buffer, NULL);
         perror(cmd->buffer);
         exit(127);
     }

kernel/src/fs/VFS.cpp

@@ -104,11 +104,7 @@ VFS::Node* VFS::resolve_path(const char* filename, Node* root)
                 return 0;
             }
             Node* child = current_node->find_func(current_node, buffer);
-            if (!child)
-            {
-                kwarnln("Current node did not find our target node");
-                return 0;
-            }
+            if (!child) { return 0; }
             if (child->flags & VFS_MOUNTPOINT)
             {
                 if (!child->link)