bgpd: Fix continue/break change from old commit

bgpd: Fix continue/break change from old commit

Commit: ea47320b1d0eeaa56f945fa356da7e4ca7f2b0b2

Modified the bgp_clear_stale_route function to have
better indentation, but in the process changed some
`continue;` statements to `break;` which modified
the looping and caused stale paths to not always be
removed upon an update.

To reproduce:  A ---- B, setup with addpath and GR
One side has a prefix with nhop1 and nhop2, kill one
side and then resend the same prefix with nhop3,
paths nhop1 and 2 become stale and never removed.

Code inspection clearly shows that that `continue`
statements became `break` statements causing the
loop over all paths to stop prematurely.

The fix is to change the break back to continue
statements so the loop can continue instead of
stopping.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>