Description: net: fix removing a namespace with conflicting altnames
References:
Notes:
 carnil> Introduced in 7663d522099e ("net: check for altname conflicts when changing
 carnil> netdev's netns"). Vulnerable versions: 6.1.60 6.5.9 6.6-rc7.
Bugs:
upstream: released (6.8-rc2) [d09486a04f5da0a812c26217213b89a3b1acf836]
6.7-upstream-stable: released (6.7.3) [8072699aa9e67d1727692cfb3c347263bb627fb9]
6.6-upstream-stable: released (6.6.15) [e855dded4b70d1975ee7b9fed0c700391e3c8ea6]
6.1-upstream-stable: released (6.1.76) [a2232f29bf52c24f827865b3c90829c44b6c695b]
5.10-upstream-stable: N/A "Vulnerable code not present"
4.19-upstream-stable: N/A "Vulnerable code not present"
sid: released (6.6.15-1)
6.1-bookworm-security: released (6.1.76-1)
5.10-bullseye-security: N/A "Vulnerable code not present"
4.19-buster-security: N/A "Vulnerable code not present"