Simplify handling of package suffix

Instead of constructing the package name from "rust-" prefix,
the name, and the suffix, let's just do it once.

rust2rpm/__main__.py

@@ -136,6 +136,10 @@ def remove_on_error(path):
         os.unlink(path)
         raise
 
+def package_name_suffixed(name, suffix):
+    joiner = '_' if suffix and name[-1].isdigit() else ''
+    return 'rust-' + name + joiner + (suffix or '')
+
 def local_toml(toml, version):
     if os.path.isdir(toml):
         doc_files = get_doc_files(toml)
@@ -504,21 +508,14 @@ def main():
         raise ValueError("No bins and no libs")
     kwargs["include_devel"] = is_lib
 
-    if args.suffix is not None:
-        if metadata.name[-1].isdigit():
-            suffix = f'_{args.suffix}'
-        else:
-            suffix = args.suffix
-    else:
-        suffix = ""
-    kwargs["pkg_suffix"] = suffix
-    spec_file = pathlib.Path(f"rust-{metadata.name}{suffix}.spec")
+    kwargs["pkg_name"] = pkg_name = package_name_suffixed(metadata.name, args.suffix)
+    spec_file = pathlib.Path(f"{pkg_name}.spec")
 
     if args.target in {"fedora"} and args.existence_check and not os.path.exists(spec_file):
         # No specfile, so this is probably a new package
-        package_info = get_package_info(f"rust-{metadata.name}{suffix}")
+        package_info = get_package_info(pkg_name)
         if package_info:
-            print(f"Crate {metadata.name}{suffix} is already packaged in Fedora ({package_info['full_url']}).")
+            print(f"Crate {pkg_name} is already packaged in Fedora ({package_info['full_url']}).")
             print("Re-run with --no-existence-check if you still want to convert it.")
             sys.exit(1)
 

rust2rpm/templates/main.spec

@@ -13,7 +13,7 @@
 %global real_crate {{ crate }}
 {% endif %}
 
-Name:           rust-%{crate}{{ pkg_suffix }}
+Name:           {{ pkg_name }}
 Version:        {{ md.version }}
 Release:        {{ pkg_release }}
 {% if md.description is none %}