lib/: sget*ent(): Simplify by calling strdup(3)

[alejandro-colomar]

While at it, rename the function parameter.

v1b

• Rebase

$ git range-diff alx/master..gh/strdup_ master..strdup_ 
1:  9b9ee9c8 = 1:  e2169576 lib/: Simplify by calling strdup(3)
2:  b81ed41a = 2:  0d41e7a6 lib/: Remove arbitrary limitation by calling strdup(3)
3:  aab18a17 = 3:  77cf47bb lib/: Rename local variable
4:  a4efdf54 = 4:  0eff731b lib/sgetpwent.c: sgetpwent(): Trim the trailing '\n'

v1c

• Rebase

$ git range-diff alx/master..gh/strdup_ master..strdup_ 
1:  e2169576 = 1:  39ab645a lib/: Simplify by calling strdup(3)
2:  0d41e7a6 = 2:  698435c5 lib/: Remove arbitrary limitation by calling strdup(3)
3:  77cf47bb = 3:  4f54e215 lib/: Rename local variable
4:  0eff731b = 4:  410ba3fb lib/sgetpwent.c: sgetpwent(): Trim the trailing '\n'

v1d

• Rebase

$ git range-diff master..gh/strdup_ shadow/master..strdup_ 
1:  39ab645a = 1:  16793a90 lib/: Simplify by calling strdup(3)
2:  698435c5 = 2:  171d9908 lib/: Remove arbitrary limitation by calling strdup(3)
3:  4f54e215 = 3:  bfc747a8 lib/: Rename local variable
4:  410ba3fb = 4:  d9c502a6 lib/sgetpwent.c: sgetpwent(): Trim the trailing '\n'

v1e

• Rebase

$ git range-diff master..gh/strdup_ shadow/master..strdup_ 
1:  16793a90 = 1:  9978c231 lib/: Simplify by calling strdup(3)
2:  171d9908 = 2:  61bf4c55 lib/: Remove arbitrary limitation by calling strdup(3)
3:  bfc747a8 = 3:  ada9c214 lib/: Rename local variable
4:  d9c502a6 = 4:  cb73a7f4 lib/sgetpwent.c: sgetpwent(): Trim the trailing '\n'