Remove exit call and mayfail parameter from physmap_common()

The only call path where exit was reached was from physmap functions.

Callers of physmap() et al. which were not prepared to handle
ERROR_PTR return values have been adjusted.
physmap_try_ro() has been renamed to physmap_ro() and physmap_common()
slightly refactored due to the now removed *FAIL parameters.

Corresponding to flashrom svn r1745.

Signed-off-by: Niklas Söderlund <niso@kth.se>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/nicintel_spi.c b/nicintel_spi.c
index 11b26c7..faceedd 100644
--- a/nicintel_spi.c
+++ b/nicintel_spi.c
@@ -177,6 +177,9 @@
 		return 1;
 
 	nicintel_spibar = rphysmap("Intel Gigabit NIC w/ SPI flash", io_base_addr, MEMMAP_SIZE);
+	if (nicintel_spibar == ERROR_PTR)
+		return 1;
+
 	/* Automatic restore of EECD on shutdown is not possible because EECD
 	 * does not only contain FLASH_WRITES_DISABLED|FLASH_WRITES_ENABLED,
 	 * but other bits with side effects as well. Those other bits must be