Fixed parsing XPM colors.

git-svn-id: https://www.imagemagick.org/subversion/ImageMagick/trunk@16757 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74
Fixed compiler warning.

git-svn-id: https://www.imagemagick.org/subversion/ImageMagick/trunk@16759 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74