LE: Fix GKI exception for 0 length values

When a remote device responds to a read request with a 0 length value, a
GKI exception will occur. This patch checks for 0 length values to avoid
the exception and return the correct status to the application
requesting the read.

Change-Id: Idce61c3d2be7072dafe429ab978763b0ee61aed2
1 file changed