stdio: Parse 0x0p+00 correctly in scanf

The scanf code was skipping the '0' after the 'x' causing the
resulting buffer to contain an invalid number when passed to strtod.

Signed-off-by: Keith Packard <keithp@keithp.com>

newlib/libc/stdio/vfscanf.c

@@ -1628,6 +1628,7 @@ __SVFSCANF_R (struct _reent *rptr,
 		      && zeroes == 1)
 		    {
 		      flags |= HEXFLT;
+                      flags &= ~NDIGITS;
 		      /* We skipped the first zero, so we have to add
 			 it now to the buffer. */
 		      *p++ = '0';