Print an error message on read errors and abort instead of proceeding anyway

Improve error checking in file write, chip read and chip verify.
Refactor the read routines a bit to split reading from file writing.

Log for a failed read:
[...]
Found chip "Winbond W25x16" (2048 KB, SPI) at physical address
0xffe00000.
Reading flash... Invalid OPCODE 0x03
Read operation failed!
FAILED.

Corresponding to flashrom svn r1079.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Stephen Kou <stephen@hyarros.com>
diff --git a/flash.h b/flash.h
index a00ad21..cd7cb46 100644
--- a/flash.h
+++ b/flash.h
@@ -579,7 +579,7 @@
 int read_memmapped(struct flashchip *flash, uint8_t *buf, int start, int len);
 int erase_flash(struct flashchip *flash);
 struct flashchip *probe_flash(struct flashchip *first_flash, int force);
-int read_flash(struct flashchip *flash, char *filename);
+int read_flash_to_file(struct flashchip *flash, char *filename);
 void check_chip_supported(struct flashchip *flash);
 int check_max_decode(enum chipbustype buses, uint32_t size);
 int min(int a, int b);