doc: Fix the Doxygen section endings

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocom/core/bits.h b/include/osmocom/core/bits.h
index b541b9c..4c68532 100644
--- a/include/osmocom/core/bits.h
+++ b/include/osmocom/core/bits.h
@@ -73,6 +73,6 @@
 /* \brief reverse the bits of each byte in a given buffer */
 void osmo_revbytebits_buf(uint8_t *buf, int len);
 
-/*! }@ */
+/*! @} */
 
 #endif /* _OSMO_BITS_H */