Global cleanup: Fix a few spelling errors

Just a trivial patch to fix a few errors found by codespell.

Here's the command I used:
codespell -S subprojects,out \
-L fwe,dout,tast,crate,parms,claus,nt,nd,te,truns,trun

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: I4e3b277f220fa70dcab21912c30f1d26d9bd8749
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/62840
Original-Reviewed-by: Felix Singer <felixsinger@posteo.net>
Original-Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Original-Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/71455
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/flash.h b/flash.h
index 0fa3129..7491335 100644
--- a/flash.h
+++ b/flash.h
@@ -74,7 +74,7 @@
 
 /*
  * The following enum defines possible write granularities of flash chips. These tend to reflect the properties
- * of the actual hardware not necesserily the write function(s) defined by the respective struct flashchip.
+ * of the actual hardware not necessarily the write function(s) defined by the respective struct flashchip.
  * The latter might (and should) be more precisely specified, e.g. they might bail out early if their execution
  * would result in undefined chip contents.
  */
@@ -177,7 +177,7 @@
 #define TEST_BAD_PREWB	(struct tested){ .probe = BAD, .read = BAD, .erase = BAD, .write = BAD, .wp = BAD }
 
 struct flashrom_flashctx;
-#define flashctx flashrom_flashctx /* TODO: Agree on a name and convert all occurences. */
+#define flashctx flashrom_flashctx /* TODO: Agree on a name and convert all occurrences. */
 typedef int (erasefunc_t)(struct flashctx *flash, unsigned int addr, unsigned int blocklen);
 
 enum flash_reg {