Null check done for correct pointer.

if (conv == NULL) means conv can be NULL, hence dereferencing it at line no 67 is illegal.
Since memory is allocated to *conv, so Null check should be done on *conv instead of conv.
If want Null check on conv also, it can be done before malloc.
Null check done for correct pointer.

Similar issue as on line no 68. Memory is allocated to *conv, so Null check should be done on *conv instead of conv.
Merge pull request #13 from ya1gaurav/patch-13

Null check done for correct pointer.