Spam in console after r336593 (NFS mounted)

[Andrey Fesenko]

Hello.
After https://svnweb.freebsd.org/base?view=revision&revision=336593
any make action starting spam errors (svn not work on NFS mounted
partitions)

svn: E155016: The working copy database at '/usr/src' is corrupt.
svn: E155016: The working copy database at '/usr/src' is corrupt.
make[2]: "/usr/src/release/Makefile.ec2" line 24: warning:
"/usr/local/bin/svn info --show-item last-changed-revision /usr/sr
c/release/.." returned non-zero status
svn: E155016: The working copy database at '/usr/src' is corrupt.
svn: E155016: The working copy database at '/usr/src' is corrupt.
make[2]: "/usr/src/release/Makefile.ec2" line 24: warning:
"/usr/local/bin/svn info --show-item last-changed-revision /usr/sr
c/release/.." returned non-zero status