GH768: Minor grammar nits in CRYPTO_get_ex_new_index.pod

Signed-off-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

doc/crypto/CRYPTO_get_ex_new_index.pod

@@ -85,7 +85,7 @@ B<idx> parameter should be an already-created index value.
 When setting exdata, the pointer specified with a particular index is saved,
 and returned on a subsequent "get" call.  If the application is going to
 release the data, it must make sure to set a B<NULL> value at the index,
-to avoid likely double-free crash.
+to avoid likely double-free crashes.
 
 The function B<CRYPTO_free_ex_data> is used to free all exdata attached
 to a structure. The appropriate type-specific routine must be used.
@@ -124,9 +124,10 @@ for B<SSL> and B<SSL_SESSION> objects.  The B<to> and B<from> parameters
 are pointers to the destination and source B<CRYPTO_EX_DATA> structures,
 respectively.  The B<srcp> parameter is a pointer to the source exdata.
 When the dup_func() returns, the value in B<srcp> is copied to the
-destination ex_data.  If the pointer contained in B<srcp> is not modified,
-then both B<to> and B<from> will point to the same data.  The B<idx>,
-B<argl> and B<argp> parameters are as described for the other two callbacks.
+destination ex_data.  If the pointer contained in B<srcp> is not modified
+by the dup_func(), then both B<to> and B<from> will point to the same data.
+The B<idx>, B<argl> and B<argp> parameters are as described for the other
+two callbacks.
 
 =head1 RETURN VALUES