Improve messages on failed erases with default verbosity

Without this...
Erasing and writing flash chip... ERASE FAILED at 0x00001000! Expected=0xff, Read=0xb4, failed byte count from 0x00000000-0x0000ffff: 0xef09
ERASE FAILED!
Reading current flash chip contents... done.
<loooooong break while the next eraser and writing is tried>
Erase/write done.
Verifying flash... VERIFIED.

Even if there is not a long temporal pause, it is very confusing for
the user to first see a failed erase, followed by a read, a done
message and eventually the verification message.
This patch inserts "Looking for another erase function." where there is
just a silent pause above.

Corresponding to flashrom svn r1827.
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>

flashrom.c

@@ -1463,9 +1463,9 @@ int erase_and_write_flash(struct flashctx *flash, uint8_t *oldcontents, uint8_t
 
 	for (k = 0; k < NUM_ERASEFUNCTIONS; k++) {
 		if (k != 0)
-			msg_cdbg("Looking for another erase function.\n");
+			msg_cinfo("Looking for another erase function.\n");
 		if (!usable_erasefunctions) {
-			msg_cdbg("No usable erase functions left.\n");
+			msg_cinfo("No usable erase functions left.\n");
 			break;
 		}
 		msg_cdbg("Trying erase function %i... ", k);