-Wdeprecated-declarations: first deprecated in OS X 10.10

fpicker/source/aqua/SalAquaFilePicker.mm:220:14: warning: 'NSOKButton' is deprecated: first deprecated in OS X 10.10 - Use NSModalResponseOK instead [-Wdeprecated-declarations]
fpicker/source/aqua/SalAquaFilePicker.mm:225:14: warning: 'NSCancelButton' is deprecated: first deprecated in OS X 10.10 - Use NSModalResponseCancel instead [-Wdeprecated-declarations]
fpicker/source/aqua/SalAquaFolderPicker.mm:114:10: warning: 'NSOKButton' is deprecated: first deprecated in OS X 10.10 - Use NSModalResponseOK instead [-Wdeprecated-declarations]
fpicker/source/aqua/SalAquaFolderPicker.mm:119:10: warning: 'NSCancelButton' is deprecated: first deprecated in OS X 10.10 - Use NSModalResponseCancel instead [-Wdeprecated-declarations]

Change-Id: Ib497903e4df868867cc56e2eade7bb2572f0902a
Reviewed-on: https://gerrit.libreoffice.org/10115
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>