Documentation: core-api: packing: correct spelling

Correct spelling problems for Documentation/core-api/packing.rst as
reported by codespell.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Vladimir Oltean <olteanv@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Link: https://lore.kernel.org/r/20230215053738.11562-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/core-api/packing.rst

@@ -161,6 +161,6 @@ xxx_packing() that calls it using the proper QUIRK_* one-hot bits set.
 
 The packing() function returns an int-encoded error code, which protects the
 programmer against incorrect API use.  The errors are not expected to occur
-durring runtime, therefore it is reasonable for xxx_packing() to return void
+during runtime, therefore it is reasonable for xxx_packing() to return void
 and simply swallow those errors. Optionally it can dump stack or print the
 error description.