Removed prefetch whole file advise in the file access.

On all my linux PC (debian sid and lenny) it has really bad side effects,
mostly when seeking and at startup up (slow or even blocking), and makes
sshfs unusable.

modules/access/file.c

@@ -322,8 +322,6 @@ static ssize_t Read( access_t *p_access, uint8_t *p_buffer, size_t i_len )
             p_access->info.i_update |= INPUT_UPDATE_SIZE;
         }
 #endif
-        /* Pre-fetch until the end (within memory limits) */
-        posix_fadvise (fd, p_access->info.i_pos, 0, POSIX_FADV_WILLNEED);
     }
     return i_ret;
 }