add coments for patch

Signed-off-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>

rust-nom.spec

@@ -13,6 +13,9 @@ License:        MIT
 URL:            https://crates.io/crates/nom
 Source0:        https://crates.io/api/v1/crates/%{crate}/%{version}/download#/%{crate}-%{version}.crate
 # Initial patched metadata
+# * Bump memchr to 2, https://github.com/Geal/nom/commit/38830cb40888ca10975e6446e133a830fe8f9604
+# * compiler_error is nightly
+# * Bump lazy_static to 1, https://github.com/Geal/nom/pull/631
 Patch0:         nom-3.2.1-fix-metadata.diff
 
 ExclusiveArch:  %{rust_arches}