ISA-L: free matrix on exit

isa_l_common_init allocates desc->matrix, but this isn't freed in
isa_l_exit. Instead, the entire isa_l_desc structure is freed,
thus leaking the memory.

Explicitly free desc->matrix.

Change-Id: Ibf672d1a309498591b87d739632a90a1b3704f7e
Signed-off-by: Daniel Axtens <dja@axtens.net>

src/backends/isa-l/isa_l_common.c

@@ -444,6 +444,7 @@ int isa_l_exit(void *desc)
 
     isa_l_desc = (isa_l_descriptor*) desc;
 
+    free(isa_l_desc->matrix);
     free(isa_l_desc);
 
     return 0;