-latomic isn't needed on FreeBSD

[yurivict]

We patch it out in the port.

[mdevaev]

Does it break compilation?

[yurivict]

Yes:

== LD ustreamer-dump.bin
ld: error: unable to find library -latomic
cc: error: linker command failed with exit code 1 (use -v to see invocation)
gmake[2]: *** [Makefile:112: ustreamer.bin] Error 1
gmake[2]: *** Waiting for unfinished jobs....
ld: error: unable to find library -latomic
cc: error: linker command failed with exit code 1 (use -v to see invocation)
gmake[2]: *** [Makefile:117: ustreamer-dump.bin] Error 1
gmake[2]: Leaving directory '/usr/ports/multimedia/ustreamer/work/ustreamer-6.13/src'
gmake[1]: *** [Makefile:46: apps] Error 2