[_AtomicShims] Don’t try to extend the library path using .linker_option

This emits a warning and it seems to be unnecessary.

Author: lorentey

Sources/_AtomicsShims/src/_AtomicsShims.c

@@ -20,7 +20,6 @@
 // Ensure we link with libswiftCore.dylib even when the build system decides
 // to build this module as a standalone library.
 // (See https://github.com/apple/swift-atomics/issues/55)
-__asm__(".linker_option \"-L/usr/lib/swift\"\n");
 __asm__(".linker_option \"-lswiftCore\"\n");
 #endif