alloc/test: Free the TBF if the recursion has failed

Currently if both an uplink and a downlink TBF are to be allocated by
alloc_tbfs() and the second allocation fails, the first TBF is not
freed.

This commit changes the recursive function to free the TBF if the ms
variable has been changed to NULL.

Sponsored-by: On-Waves ehf
1 file changed