spi25_statusreg: delete spi_read_status_register()

Delete the spi_read_status_register() function because the generic
spi_read_register() function can be used instead.

This patch also converts all call sites over to spi_read_register().
A side effect is that error codes are now properly propagated and
checked.

Tested: flashrom -{r,w,E}
Tested: Tested with a W25Q128.W flash on a kasumi (AMD) dut.
     Read SR1/SR2 with --wp-status and activated various WP ranges
     that toggled bits in both SR1 and SR2.

Change-Id: I146b4b5439872e66c5d33e156451a729d248c7da
Signed-off-by: Nikolai Artemiev <nartemiev@google.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/59529
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Original-Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/70975
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/spi25.c b/spi25.c
index 2a1d492..c5832fb 100644
--- a/spi25.c
+++ b/spi25.c
@@ -286,12 +286,17 @@
 
 static int spi_poll_wip(struct flashctx *const flash, const unsigned int poll_delay)
 {
-	/* FIXME: We can't tell if spi_read_status_register() failed. */
 	/* FIXME: We don't time out. */
-	while (spi_read_status_register(flash) & SPI_SR_WIP)
+	while (true) {
+		uint8_t status;
+		int ret = spi_read_register(flash, STATUS1, &status);
+		if (ret)
+			return ret;
+		if (!(status & SPI_SR_WIP))
+			return 0;
+
 		programmer_delay(poll_delay);
-	/* FIXME: Check the status register for errors. */
-	return 0;
+	}
 }
 
 /**