Fix typo in crl2pkcs documentation

Fixes #13910

CLA: trivial

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13911)

(cherry picked from commit 6857058016e91d3182c2117922dd8001b27f5639)

doc/man1/crl2pkcs7.pod

@@ -56,7 +56,7 @@ output by default.
 
 Specifies a filename containing one or more certificates in B<PEM> format.
 All certificates in the file will be added to the PKCS#7 structure. This
-option can be used more than once to read certificates form multiple
+option can be used more than once to read certificates from multiple
 files.
 
 =item B<-nocrl>