Combining multiple dataframes in a list

I have a list containing multiple dataframes. Depending on whether the
dataframes have 1 column or more than 1 columns, the column names are
named differently. How can I force single column dataframes to have
prefixed column names ?

m<- list(fc=data.frame(A=1:3))
do.call(cbind, m)

A
1 1
2 2
3 3

m<- list(fc=data.frame(A=1:3, B=2:4))
do.call(cbind, m)

fc.A fc.B
1    1    2
2    2    3
3    3    4