Core: unconditionally include stdio.h in libdivecomputer.h

Header files should compile regardless of order of inclusion.
Since libdivecomputer.h uses FILE unconditional include of
stdio.h is the correct thing to do.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/libdivecomputer.h

@@ -3,9 +3,7 @@
 #define LIBDIVECOMPUTER_H
 
 #include <stdint.h>
-#if defined(Q_OS_IOS)
 #include <stdio.h>
-#endif
 
 /* libdivecomputer */