cmake: remove Darwin/resolv quirks

Since commit e98a32373 ("core: check if res_init requires linking with
libresolv") we detect if/when we should be linking against libresolv.

The detection seems a bit clunky (to me), although it's better to keep
things consolidated/consistent across tree. Swap the Darwin checks with
the new token LIBRESOLV_HAS_RES_INIT.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

src/plugins/irc/CMakeLists.txt

@@ -59,9 +59,8 @@ list(APPEND LINK_LIBS ${GNUTLS_LDFLAGS})
 
 list(APPEND LINK_LIBS ${LIBGCRYPT_LDFLAGS})
 
-if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-  # link with resolv lib on macOS
-  list(APPEND LINK_LIBS "resolv")
+if(LIBRESOLV_HAS_RES_INIT)
+  list(APPEND LINK_LIBS ${RESOLV_LIBRARY})
 endif()
 
 target_link_libraries(irc ${LINK_LIBS} coverage_config)

src/plugins/xfer/CMakeLists.txt

@@ -38,9 +38,8 @@ set(LINK_LIBS)
 
 list(APPEND LINK_LIBS ${LIBGCRYPT_LDFLAGS})
 
-if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-  # link with resolv lib on macOS
-  list(APPEND LINK_LIBS "resolv")
+if(LIBRESOLV_HAS_RES_INIT)
+  list(APPEND LINK_LIBS ${RESOLV_LIBRARY})
 endif()
 
 target_link_libraries(xfer ${LINK_LIBS} coverage_config)