fix bogus assertion in encode_comp_field()

Fix an obvious logic bug in an assertion in encode_comp_field().

Found by: Neels

Change-Id: If6f3598cd6da4643ff2214e21c0d21f6eff0eb67
diff --git a/src/gprs/gprs_sndcp_xid.c b/src/gprs/gprs_sndcp_xid.c
index 8f844b5..09e21f5 100644
--- a/src/gprs/gprs_sndcp_xid.c
+++ b/src/gprs/gprs_sndcp_xid.c
@@ -443,7 +443,7 @@
 	OSMO_ASSERT(comp_field->entity <= 0x1f);
 
 	/* Check if the algorithm number is within bounds */
-	OSMO_ASSERT(comp_field->algo >= 0 || comp_field->algo <= 0x1f);
+	OSMO_ASSERT(comp_field->algo >= 0 && comp_field->algo <= 0x1f);
 
 	/* Zero out buffer */
 	memset(dst, 0, dst_maxlen);