scripts/spelling.txt: add "againt" pattern and fix typo instances

Fix typos and add the following to the scripts/spelling.txt:

againt||against

While we are here, fix the "capabilites" as well in the touched hunk in
drivers/gpu/drm/drm_probe_helper.c.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Masahiro Yamada <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/gpu/drm/drm_probe_helper.c

···
  *    - drm_mode_validate_basic() performs basic sanity checks
  *    - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
  *      (if specified)
- *    - drm_mode_validate_flag() checks the modes againt basic connector
- *      capabilites (interlace_allowed,doublescan_allowed,stereo_allowed)
+ *    - drm_mode_validate_flag() checks the modes against basic connector
+ *      capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
  *    - the optional &drm_connector_helper_funcs.mode_valid helper can perform
  *      driver and/or hardware specific checks
  *

fs/ecryptfs/kthread.c

···
  * @lower_dentry: Lower dentry for file to open
  * @lower_mnt: Lower vfsmount for file to open
  *
- * This function gets a r/w file opened againt the lower dentry.
+ * This function gets a r/w file opened against the lower dentry.
  *
  * Returns zero on success; non-zero otherwise
  */

scripts/spelling.txt

···
 adresses||addresses
 adviced||advised
 afecting||affecting
+againt||against
 agaist||against
 albumns||albums
 alegorical||allegorical