scripts/runqemu: fix a typo

(From OE-Core rev: c72d5acb9c2f4a7d4dfe0e78aae832b10aec4429)

Signed-off-by: Ming Liu <peter.x.liu@external.atlascopco.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/runqemu

@@ -96,7 +96,7 @@ Examples:
 """)
 
 def check_tun():
-    """Check /dev/net/run"""
+    """Check /dev/net/tun"""
     dev_tun = '/dev/net/tun'
     if not os.path.exists(dev_tun):
         raise Exception("TUN control device %s is unavailable; you may need to enable TUN (e.g. sudo modprobe tun)" % dev_tun)