updated for version 7.3.191

Problem:    Still some RISC OS stuff to remove.
Solution:   Remove files and lines. (Hong Xu)
            Remove the 'osfiletype' option code.

src/structs.h

@@ -1530,9 +1530,6 @@ struct file_buffer
     int		b_p_ml_nobin;	/* b_p_ml saved for binary mode */
     int		b_p_ma;		/* 'modifiable' */
     char_u	*b_p_nf;	/* 'nrformats' */
-#ifdef FEAT_OSFILETYPE
-    char_u	*b_p_oft;	/* 'osfiletype' */
-#endif
     int		b_p_pi;		/* 'preserveindent' */
 #ifdef FEAT_TEXTOBJ
     char_u	*b_p_qe;	/* 'quoteescape' */