Remove redundant return code check. NFC (#1749)

The `subprocess.check_call` function will throw rather than return a
non-zero error code so this is dead code.

emsdk.py

diff --git a/emsdk.py b/emsdk.py
index 2576355..4f3a4be 100644
--- a/emsdk.py
+++ b/emsdk.py
@@ -1001,11 +1001,7 @@
     # Create a file 'recmake.bat/sh' in the build root that user can call to
     # manually recmake the build tree with the previous build params
     open(os.path.join(build_root, 'recmake.' + ('bat' if WINDOWS else 'sh')), 'w').write(' '.join(map(quote_parens, cmdline)))
-    ret = subprocess.check_call(cmdline, cwd=build_root, env=build_env())
-    if ret != 0:
-      errlog(f'CMake invocation failed with exit code {ret}')
-      errlog(f'Working directory: {build_root}')
-      return False
+    subprocess.check_call(cmdline, cwd=build_root, env=build_env())
   except OSError as e:
     if e.errno == errno.ENOENT:
       errlog(str(e))