softap: Fix KW issue for array index out of bounds

Check the length of the buffer before using it calculate
the index of the data in the buffer to prevent index becoming
a negative value.

Change-Id: I3dc440dac2e4a5437e2ff70c39577876a3a97123
CRs-fixed: 2111307
1 file changed
tree: 5060b8ab39139fdec4c3360a02b9a90734157095
  1. softap/