search: Fix 'name' leak

In an earlier version, the result of `clib_package_parse_name` didn't need to be freed.


## Before

$ valgrind --leak-check=full ./clib-search str foo > /dev/null
==25106== Memcheck, a memory error detector
==25106== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==25106== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==25106== Command: ./clib-search str foo
==25106== 
==25106== 
==25106== HEAP SUMMARY:
==25106==     in use at exit: 573 bytes in 64 blocks
==25106==   total heap usage: 13,620 allocs, 13,556 frees, 1,658,352 bytes allocated
==25106== 
==25106== 573 bytes in 64 blocks are definitely lost in loss record 1 of 1
==25106==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==25106==    by 0x41CC4D: str_copy (in /home/stephen/clib/clib-search)
==25106==    by 0x41A9D9: parse_repo_name (in /home/stephen/clib/clib-search)
==25106==    by 0x4031D1: clib_package_parse_name (in /home/stephen/clib/clib-search)
==25106==    by 0x401995: matches (in /home/stephen/clib/clib-search)
==25106==    by 0x401CB3: main (in /home/stephen/clib/clib-search)
==25106== 
==25106== LEAK SUMMARY:
==25106==    definitely lost: 573 bytes in 64 blocks
==25106==    indirectly lost: 0 bytes in 0 blocks
==25106==      possibly lost: 0 bytes in 0 blocks
==25106==    still reachable: 0 bytes in 0 blocks
==25106==         suppressed: 0 bytes in 0 blocks
==25106== 
==25106== For counts of detected and suppressed errors, rerun with: -v
==25106== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 2 from 2)

## After

$ valgrind --leak-check=full ./clib-search str foo > /dev/null
==25272== Memcheck, a memory error detector
==25272== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==25272== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==25272== Command: ./clib-search str foo
==25272== 
==25272== 
==25272== HEAP SUMMARY:
==25272==     in use at exit: 0 bytes in 0 blocks
==25272==   total heap usage: 13,620 allocs, 13,620 frees, 1,658,352 bytes allocated
==25272== 
==25272== All heap blocks were freed -- no leaks are possible
==25272== 
==25272== For counts of detected and suppressed errors, rerun with: -v
==25272== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)