configure.ac: check xmp_set_player instead of xmp_version

Autoconf checks the symbol by doing a "return xmp_version ();" from
main(), and the MorphOS linker fails it with the error message:
 The target (xmp_version) of a R_PPC_REL24 relocation is in the wrong section (.sdata)

well, xmp_version is data...

configure.ac

@@ -32,8 +32,9 @@ AM_INIT_AUTOMAKE([foreign subdir-objects tar-pax])
 old_LDFLAGS="${LDFLAGS}"
 PKG_CHECK_MODULES([libxmp], [libxmp >= 4.4],
   LDFLAGS="${LDFLAGS} ${libxmp_LIBS}"
-  AC_CHECK_LIB(xmp, xmp_version, [LDFLAGS="${old_LDFLAGS}"], [exit 1]),
-  [echo "You need libxmp version 4.4 or later to build this package"; exit 1])
+  AC_CHECK_LIB(xmp, xmp_set_player, [LDFLAGS="${old_LDFLAGS}"], [exit 1]),
+  [echo "You need libxmp version 4.4 or later to build this package"; exit 1]
+)
 
 dnl Don't use things like /usr/etc or /usr/var